The present invention relates in general to a double seat valve of the type defining an annular leakage fluid collecting space or chamber between two valve disks and an annular discharge conduit which communicates with a bottom portion of the chamber to discharge the leakage liquid. In particular, the invention relates to a method of and a device for cleaning this annular chamber.
With increasing automation of beverage processing plants, it is required to provide an automatic cleaning of paths of flow of the processed produce. For this purpose, program control chemical cleaning methods have been developed in which the cleaning steps can be remotely controlled. In this known process, valves are employed by means of which both occasional and fixedly determined operational cycles are controlled. In using control valves of this kind, for example in tank batteries, the individual operational cycles such as filling, discharging, cleaning and disinfecting must be carried out in simple manner. Due to the strict safety requirements, it is necessary that cleaning liquids be completely separated from the processed product. For this reason, especially in the beverage industry, double seat valves with two valve disks are used. The two disk valves of each double seat valve bound a hollow space therebetween which communicates with a leakage fluid discharge conduit. The free end of the latter conduit, which is remote from the valve seat, opens in the atmosphere. In this manner, any defective seal of the valve can be readily detected from the amount of discharged leaking liquid, and the sealing defect can be removed before major damage occurs.
In order to clean the discharge space for the leaking liquid, a spray pipe has been arranged within the outer part of the discharge conduit for the leaking fluid. It has been found, however, that the application of such a spraying pipe for attacking the hollow space with cleaning liquid is insufficient for achieving all desired effects.